Muscle Gain: How Heavy Should You Lift To Grow

Muscle Gain: How Heavy Should You Lift To Grow

Intensity: Leading Variable of Muscle Gain.


Intensity is one of the most important variables when it comes to muscle gain (hypertrophy). It refers to the amount of weight lifted during a particular workout set and it is measured as a percentage of a max repetition. (RM – rep max)


RM – Max amount of weight you can lift a given amount of times with good form.

1 RM – Weight you can lift once but not twice.

10 RM – Weight you can lift 10 times but not 11.


The weight used for a given exercise should be heavy enough to recruit and fatigue the full spectrum of muscle fibers in order for it to lead to hypertrophy.

Training intensity has a strong correlation to the number of reps you can perform at a particular exercise. (This is called REP RANGE)


There are 3 different rep ranges:

  1. Low rep range (1 to 5 reps) –  Excellent for strength gains, will lead to increases in muscle mass but not ideal.
  2. Moderate  rep range (6 to 12 reps) – 65% – 85% of RM – Optimal for hypertrophy.
  3. High rep range (15+) – Excellent for better muscle endurance, sub-optimal for muscle gain.


Just because moderate rep ranges seem optimal, do not disregard the other rep ranges. For an excellent physique you should train in ALL rep ranges!


It is important to cycle between low rep range training to medium rep range and even high rep ranges, it all depends on your personal preference, exercise selection and fitness level.


If your goal is to get bigger muscles, try to get stronger (train within the low rep range), get the best of all three (mechanical tension, muscle damage and metabolic stress) by training in the medium rep range and increase your endurance and add a lot of metabolic stress by training in the high rep spectrum.


More on how, in the article about exercise selection!


Written by:

Coach Paul Potora, Dietitian, Personal trainer and Founder of CORE.

You can find me on Instagram: @potorafit

Sources: Brad Schoenfeld – Max Muscle Plan